KR102194518B1 - Hydrogenated isotope-rich boron trifluoride dopant source gas composition - Google Patents

Abstract

The present invention relates to hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas compositions. The composition comprises (i) boron trifluoride in which the atomic mass of 11 boron ( ¹¹ B) is isotope-rich than the natural abundance, and (ii) 2 to 6.99 volumes based on the total volume of boron trifluoride and hydrogen in the composition. % Contains hydrogen. In addition, a method of using the dopant source gas composition and a device related thereto are described.

Description

Hydrogenated isotope-rich boron trifluoride dopant source gas composition

The present invention relates to a hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition and related methods and apparatus for use in ion implantation.

Cross-reference of related applications

This application claims the priority of U.S. Provisional Patent Application No. 62/314241 (name: "Hydrogenated Isotope-Enriched BF ₃ Dopant Source Gas Composition") filed March 28, 2016, which is incorporated herein by reference in its entirety. It is cited for reference.

Ion implantation is used in integrated circuit fabrication to accurately introduce a controlled amount of dopant impurities into a semiconductor wafer during microelectronic/semiconductor fabrication. In this implantation system, the ion source ionizes the desired dopant element gas, and the ions are extracted from the source in the form of an ion beam of desired energy. Extraction is achieved by applying a high voltage to an extraction electrode of an appropriate shape, which contains an aperture for passing the extracted beam. Then, an ion beam is directed to implant the dopant element onto the surface of a work piece such as a semiconductor wafer. The ions in the beam penetrate the surface of the work piece to form the desired conductive region.

Several types including microwave type, magnetron, indirectly heated cathode (IHC) source and RF plasma source using Freeman and Bernas types using thermal electrodes and powered by an electric arc Ion sources of are used in ion implantation systems, all of which typically operate under vacuum. In some systems, the ion source generates ions by introducing electrons into a vacuum arc chamber (hereinafter “chamber”) filled with a dopant gas (generally referred to as “feedstock gas”). The collision of electrons with atoms and molecules in the dopant gas creates an ionized plasma composed of cation and anion dopant ions. An extraction electrode with a negative or positive bias will each allow positive or negative ions to pass through the aperture as a collimated ion beam accelerated towards the target material.

In many ion implantation processes, boron is implanted in the manufacture of integrated circuit devices. Boron is generally injected from a feedstock gas such as boron trifluoride.

Tungsten is generally used as a building material for filament elements and other cathode structures in ion implantation systems. A persistent problem with the use of such materials in the ion source chamber of ion implantation systems is the problem of tungsten loss, which can lead to filament thinning or so-called "punch through" of the cathode structure. And this requires re-metallization or replacement of the cathode structure. In extreme cases, sputtering of tungsten from the cathode can lead to a very short operating life of the ion source before such re-metallization or replacement is required. Tungsten loss from the cathode is related to the unwanted deposition of tungsten on the ion source chamber surface and the unwanted tungsten beam contribution to the ion beam generated in the system. Therefore, the loss of tungsten may cause the ion beam instability, which may lead to premature damage to the ion source.

The present invention relates to a hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition and associated method and apparatus for use in ion implantation.

In one aspect, the present invention relates to a hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition, wherein (i) boron of atomic mass 11 ( ¹¹ B) is isotope-rich than its natural abundance. Boron trifluoride, and (ii) hydrogen in an amount of 2 to 6.99% by volume, based on the total volume of boron trifluoride and hydrogen in the composition.

In another aspect, the present invention relates to a hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition, wherein (i) boron of atomic mass 11 ( ¹¹ B) is an isotope in excess of 99%. -Rich boron trifluoride, and (ii) hydrogen in an amount of 5% by volume, based on the total volume of boron trifluoride and hydrogen in the composition.

In a further aspect, the present invention relates to a hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition, wherein (i) boron of atomic mass 11 ( ¹¹ B) is more isotope than its natural abundance. It consists essentially of rich boron trifluoride, and (ii) hydrogen in an amount of 2 to 6.99% by volume, based on the total volume of boron trifluoride and hydrogen in the composition. More specifically, hydrogen is in the range of 2 to 6.5% by volume based on the total volume of boron trifluoride and hydrogen in the composition, in the range of 2.5 to 6.25% by volume based on the total volume of boron trifluoride and hydrogen in the composition, 3 to 6% by volume based on the total volume of boron trifluoride and hydrogen in the composition, 4 to 6% by volume based on the total volume of boron trifluoride and hydrogen in the composition, or boron trifluoride and May be present in any suitable amount of 5 vol% based on the total volume of hydrogen, and the specific amount or range of amounts used may be selected to achieve a desired level of operational performance or improvement for a specific application. Will understand.

Another aspect of the present invention is a boron dopant gas composition supply package comprising a gas storage and distribution container containing a hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition according to various embodiments disclosed herein. It is about.

Another aspect of the present invention is the steps of ionizing a hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition to produce a boron-containing ionic implanted species according to various embodiments disclosed herein, and the It relates to a method of forming a boron-infused substrate comprising the step of implanting a boron-containing implanted species into the substrate.

Another aspect of the invention is the steps of introducing a hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition according to various embodiments disclosed herein into an ion source chamber of an ion implantation system, and the hydrogenated An isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition is ionized in the ion source chamber to generate a boron-containing implanted species for boron ion implantation.

The present invention relates to boron from a boron dopant gas supply package comprising a gas storage and distribution vessel holding a hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition according to various embodiments of the invention described herein. A method of improving the operation of an ion implantation system comprising flowing a dopant gas composition into the ion implantation system.

Another aspect of the present invention relates to a method for reducing tungsten cathode erosion in a boron ion implantation system having a tungsten cathode, the method comprising: hydrogenated hydrogenation according to various embodiments of the present invention described herein. Ionization of the isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition to generate boron ion implantation species for implantation of boron ions into the system.

Another aspect of the invention is a boron comprising a hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition according to various embodiments of the invention described herein for use in a boron ion implantation system. It relates to a method of improving the operational performance of a boron ion implantation system comprising supplying a dopant source gas composition.

In a further aspect, the invention provides a boron ion implantation system from a boron dopant source gas composition comprising a hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition according to various embodiments of the invention described herein. It relates to a method of improving the operating performance of a boron ion implantation system, comprising generating a boron implanted species at.

In a further aspect, the present invention relates to a method of improving the beam stability and ion source lifetime of a boron doped ion implantation system including a cathode, the method comprising: a boron dopant source gas composition as an ion source of a boron doped ion implantation system. Introducing into the chamber, by operating the boron doped ion implantation system to ionize the boron dopant source gas composition in the ion source chamber, generate a beam of boron dopant species, and send it to a substrate in the ion implantation system for ion implantation. Boron doping a substrate in the system with a boron dopant species, wherein the dopant source gas composition comprises: (i) boron trifluoride having an atomic mass of 11 boron ( ¹¹ B) isotope-rich than its natural abundance, and ( ii) hydrogen in an amount of 2 to 6.99% by volume based on the total volume of boron trifluoride and hydrogen in the composition, and the reduction in beam current is less than 8%. More specifically, hydrogen is in the range of 2 to 6.5% by volume based on the total volume of boron trifluoride and hydrogen in the composition, in the range of 2.5 to 6.25% by volume based on the total volume of boron trifluoride and hydrogen in the composition, 3 to 6% by volume based on the total volume of boron trifluoride and hydrogen in the composition, 4 to 6% by volume based on the total volume of boron trifluoride and hydrogen in the composition, or boron trifluoride and May be present in any suitable amount of 5 vol% based on the total volume of hydrogen, and the specific amount or range of amounts used may be selected to achieve a desired level of operational performance or improvement for a specific application. Will understand.

In yet another aspect, the present invention comprises (a) ¹¹ B-isotope-rich boron trifluoride from the first gas supply package and (b) hydrogen gas from the second gas supply package, (i) atomic mass 11 Ion source comprising boron trifluoride in which the boron of ( ¹¹ B) is isotope-rich than its natural abundance, and (ii) hydrogen in an amount of 2 to 6.99% by volume based on the total volume of boron trifluoride and hydrogen in the composition. A method of operating an ion implantation system comprising co-flowing into an ion source chamber of an ion implantation system with the relative ratio of the boron trifluoride and hydrogen constituting the dopant source gas composition in the chamber. More specifically, hydrogen is in the range of 2 to 6.5% by volume based on the total volume of boron trifluoride and hydrogen in the composition, in the range of 2.5 to 6.25% by volume based on the total volume of boron trifluoride and hydrogen in the composition, 3 to 6% by volume based on the total volume of boron trifluoride and hydrogen in the composition, 4 to 6% by volume based on the total volume of boron trifluoride and hydrogen in the composition, or boron trifluoride and May be present in any suitable amount of 5 vol% based on the total volume of hydrogen, and the specific amount or range of amounts used may be selected to achieve a desired level of operational performance or improvement for a specific application. Will understand.

The foregoing summary is provided to facilitate understanding of some of the innovative features inherent in the present invention, and is not intended to be a complete description. A complete understanding of the present invention can be obtained by taking the entire specification, claims, drawings, and abstract as a whole.

The invention may be more fully understood in consideration of the following description of various exemplary embodiments in connection with the accompanying drawings.
1 is a schematic cross-sectional view of a fluid supply package comprising a pressure-controlled fluid storage and dispensing vessel, wherein a hydrogenated concentrated boron trifluoride dopant source gas composition according to various embodiments of the present invention comprises storage and May be provided for distribution.
2 is a schematic diagram of an ion implantation system illustrating a mode of operation according to the present invention, wherein the hydrogenated boron trifluoride dopant source gas composition of the present invention is supplied to an ion implanter to implant boron into a substrate.
Figure 3 shows the hydrogen/boron trifluoride co-flow ratio (volume H ₂ /volume from 0 to 0.6) flowing into the ion chamber of the ion implantation apparatus with an isotope-rich BF ₃ flow rate of 2.75 standard cubic centimeters per minute (sccm). BF ₃ ) is a graph of the B+ beam current as a function of, which shows the beam performance of a hydrogenated isotope-rich boron trifluoride dopant source gas composition according to various embodiments of the present invention.
Figure 4, (i) only the substantially pure (> 99.95 vol%) ¹¹ BF flow, (ii) of the lower H ^_2/11 BF ₃ by volume, substantially pure (> 99.95 vol%) ¹¹ BF ₃ and hydrogen in the co-flow, and (iii) a high H ^_2/11 BF ₃ by volume, of substantially pure hydrogen (> 99.95 vol%) ¹¹ BF ₃ and hydrogen in the ball-of, 170-300AMU range shown for flow W + and WF _x + (x = 1, 2, 3, 4, 5 and 6) for B+, F+, HF+, BF+, BF2+ and W++ ions by an inset spectrum segment representing the beam current values for the ions. This is a graph comparing the beam spectrum of the beam current in milliamps as a function of the atomic mass unit (AMU) value showing the beam current value.
5 is a graph of 0 to shown in milliamps as a function of the 0.6 H ^_2/11 BF ₃ volume ratio of F +, HF +, W +, and WF + beam current, wherein for data for each of the ionic species is F + diamond symbol ( ◆), HF+ is indicated by a circular dot symbol (●), W+ is indicated by a square symbol (■), and WF+ is indicated by a triangle symbol (▲). The boron trifluoride used to generate these data was substantially pure (> 99.95 vol%) ¹¹ BF ₃ .
6 is shown in milliamps as a function of 0 to 0.6 H ^_2/11 BF ₃ volume ratio of, F +, as a normalized graph corresponding to the HF +, W +, and WF + beam current, where x is in the H ₂ / BF ₃ ratio And the F+, HF+, W+, and WF+ beam currents were normalized to the B+ beam current, where the data for each ionic species is a diamond symbol (◆) for F+, a circular dot symbol (●), and W+ for HF+. Is indicated by a square symbol (■) and for WF+ by a triangle symbol (▲).
Figure 7 shows B+, F+, HF+, BF+, by inset spectral segments representing beam current values for W+ and WF _x + (x = 1, 2, 3, 4, 5 and 6) ions in the 170-300 AMU range. A comparison graph of the beam spectrum of the beam current in milliamps as a function of atomic mass unit (AMU) values showing the beam current values for BF2+ and W++ ions, where the ion implantation system is substantially non-hydrogenated in both cases. Using pure (> 99.95 vol%) ¹¹ BF ₃ , it was tuned for the B+ ion implantation species in the first run and the BF ₂ + ion implantation species in the second run.
Figure 8 shows B+, F+, HF+, BF+, by inset spectral segments representing beam current values for W+ and WF _x + (x = 1, 2, 3, 4, 5 and 6) ions in the 170-300 AMU range. A beam spectrum comparison graph of the beam current in milliamps as a function of atomic mass unit (AMU) values showing beam current values for BF2+ and W++ ions, wherein the ion implantation system is substantially non-hydrogenated in the first run. Pure (> 99.95 vol%) ¹¹ BF ₃ was used for B+ ion implantation species (green spectrum) and substantially pure (> 99.95 vol%) ¹¹ BF ₃ hydrogenated in the second run in the second run was used. and BF ₂ + ion implantation was adjusted for the kinds (red spectrum; the H ^_2/11 BF ₃ optimization of volume ratio 0.05).
Figure 9 is B+, F+, HF+, BF+, by inset spectral segments representing beam current values for W+ and WF _x + (x = 1, 2, 3, 4, 5 and 6) ions in the 170-300 AMU range. A beam spectrum comparison graph of the beam current in milliamps as a function of atomic mass unit (AMU) values showing beam current values for BF2+ and W++ ions, wherein the ion implantation system is substantially non-hydrogenated in the first run. Pure (> 99.95 vol%) ¹¹ BF ₃ was used for B+ ion implantation species (green spectrum) and substantially pure (> 99.95 vol%) ¹¹ BF ₃ hydrogenated in the second run in the second run was used. and BF ₂ + ion implantation was adjusted for the kinds (red spectrum; the H ^_2/11 BF ₃ optimization of volume ratio 0.05).
10 is a graph showing the change in cathode weight per hour plotted against the volume percent of hydrogen gas having B+ implanted ions.
11 is a graph showing the change in anti-cathode mass per hour plotted against the volume percent of hydrogen gas having B+ implanted ions.
12 is a graph showing the change in cathode weight per hour plotted against the volume percent of hydrogen gas having BF ₂ + implanted ions.
13 is a graph showing the change in anti-cathode mass per hour plotted against the volume percent of hydrogen gas with BF ₂ + implanted ions.
The invention can be applied to various modifications and alternative forms, but the details thereof will be shown by way of example in the drawings and will be described in detail. However, it is to be understood that it is not intended to limit aspects of the invention to the specific exemplary embodiments described. Conversely, it is intended to cover all modifications, equivalents and alternatives that fall within the spirit and scope of the present invention.

The following detailed description should be read with reference to the drawings, and similar elements in different drawings are numbered the same. The detailed description and drawings (not necessarily to scale) illustrate exemplary embodiments and are not intended to limit the scope of the invention. The illustrated exemplary embodiments are intended as examples only. Selected features of any exemplary embodiment may be incorporated into further embodiments, unless expressly stated otherwise.

The singular form used in this specification and the appended claims includes the plural subject unless the context specifies otherwise.

As used herein, the term “pressure-controlled” for fluid storage and dispensing vessels means that such vessels are at least one pressure regulator device disposed within the inner volume of the vessel and/or within the valve head of the vessel, Means to have a set pressure valve or a vacuum/pressure activated check valve, wherein each pressure regulating device responds to the fluid pressure in the fluid flow path immediately downstream of the pressure regulating device, and upstream of the pressure regulating device. Open at a specific downstream decompression condition for the higher fluid pressure of the unit to allow fluid flow and, after such opening, is adapted to operate to maintain the pressure of the fluid discharged from the pressure regulator device at a specific or “set point” pressure level. do.

The present invention relates to a hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition and related methods and apparatus having utility in ion implantation to generate ionic boron species for implantation into a substrate. In this case, high-efficiency ion implantation is performed in the manufacture of products such as semiconductor devices, flat panel displays, and solar panels. The hydrogenated isotope-rich boron trifluoride composition of the present invention substantially reduces the amount of undesired beam components including tungsten and tungsten fluoride ionic species, while maintaining a high boron ion beam current to increase the lifetime of the cathode. By making it possible to extend, the high efficiency obtained by the use of isotope-rich boron trifluoride is improved, and the maintenance required by the ion implantation equipment is reduced, for example in connection with cathode re-metallization and replacement. Let it.

The hydrogenated isotope-rich boron trifluoride compositions of the present invention may, in various embodiments, comprise, consist essentially of, or consist of boron trifluoride and hydrogen components variously disclosed herein. In any of the compositions, methods and devices disclosed herein described as comprising a component, part or subassembly, other embodiments of such compositions, methods and devices, as applicable, consist of, or consist of such components, parts or assemblies, or It will be understood that can be used in an essentially accomplished state.

In one embodiment, the present invention relates to a hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition, wherein (i) boron of atomic mass 11 ( ¹¹ B) is more isotope than its natural abundance. Boron trifluoride enriched, and (ii) hydrogen in an amount of 2 to 6.99% by volume, based on the total volume of boron trifluoride and hydrogen in the composition.

In various embodiments of the hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition of the present invention, boron trifluoride having an atomic mass of 11 boron ( ¹¹ B) than its natural abundance is 80.1 %, 85%, 88%, 90%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9%, 99.99%, 99.995%, and 99.999% So it can be rich in isotopes.

In another embodiment of the hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition of the present invention, boron trifluoride having an atomic mass of 11 boron ( ¹¹ B) isotopically-rich than its natural abundance is 81 To 85%, 85 to 90%, 90 to 95%, 95 to 99%, and 95 to 100%.

In various embodiments of the present invention, boron trifluoride, which has an atomic mass of 11 boron ( ¹¹ B) than its natural abundance, is 100% isotope rich.

In one aspect, the present invention relates to a hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition, which (i) has an atomic mass of 11 boron ( ¹¹ B) in excess of 99% isotope- Boron trifluoride enriched, and (ii) hydrogen in an amount of 5 vol% based on the total volume of boron trifluoride and hydrogen in the composition.

In another aspect, the present invention relates to a hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition, wherein (i) boron with an atomic mass of 11 ( ¹¹ B) is more isotope than its natural abundance. It consists essentially of rich boron trifluoride, and (ii) hydrogen in an amount of 2 to 6.99% by volume, based on the total volume of boron trifluoride and hydrogen in the composition.

In various embodiments of the aforementioned hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition, hydrogen ranges from 2 to 6.5% by volume, based on the total volume of boron trifluoride and hydrogen in the composition, wherein From 2.5 to 6.25% by volume based on the total volume of boron trifluoride and hydrogen in the composition, from 3 to 6% by volume based on the total volume of boron trifluoride and hydrogen in the composition, of boron trifluoride and hydrogen in the composition It can be present in any suitable amount ranging from 4 to 6% by volume based on the total volume, or 5% by volume based on the total volume of boron trifluoride and hydrogen in the composition, the specific amount or the range used It is understood that it may be selected to achieve a desired level of operational performance or improvement for the application.

A further aspect of the present invention is a boron dopant gas comprising a gas storage and distribution vessel containing a hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition according to various embodiments of the present invention disclosed herein. It relates to a composition supply package.

Such a supply package, wherein the gas storage and distribution container may be configured to include an internal pressure-controlled gas storage and distribution container, for example the internal pressure-controlled gas storage and distribution container of the package A series of gas pressure regulators disposed therein, through which the gas flows in the dispensing action (for example, can be used to dispense a hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition at subatmospheric pressure) It may include. Alternatively, the internal pressure-controlled gas storage and distribution vessel may be in the range of atmospheric pressure to superatmospheric pressure, for example atmospheric pressure to 200 psig (1.38 megapascals (MPa)), or in the low superatmospheric pressure range, e. 0.069 MPa) to 200 psig (1.38 MPa) or in other embodiments 50 psig (0.0345 MPa) to 150 psig (1.034 MPa) at an appropriate pressure level.

The present invention provides the steps of ionizing a hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition variously described herein to produce a boron-containing ionic implanted species, and the boron-containing implanted species. Further contemplated is a method of forming a boron-implanted substrate comprising implanting into the substrate. Boron-containing ionic species may be a type injecting any suitable, for example, may include B +, B ++, B +++ , BF 2 +, BF 2 ++ , or any other advantageous injecting boron species.

Another aspect of the invention is the steps of introducing a hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition according to the invention variously described herein into an ion source chamber of an ion implantation system, and the hydrogenation. An isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition is directed to a boron ion implantation method comprising the step of ionizing in an ion source chamber to generate a boron-containing implant species for boron ion implantation. The method may further include generating a beam of boron-containing implanted species, and sending the beam to a substrate to implant the boron-containing implanted species therein. Alternatively, the method may include exposing the substrate to a boron-containing implanted species for ion implantation into the substrate, wherein such exposure may be performed by any suitable process or technique, such as plasma-assisted ion implantation, mass spectrometry. It includes beamline injection by means of, beamline injection without using a mass analyzer, and plasma immersion.

The above-described method may be performed in a method of manufacturing a product selected from the group consisting of a semiconductor product, a flat-panel display product, and a solar panel product.

In a further aspect the present invention provides a gas storage and distribution vessel containing a hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition according to various embodiments disclosed herein, for use in an ion implantation system. It relates to a method of improving the operation of an ion implantation system, comprising providing a boron dopant gas composition supply package comprising.

Another aspect of the present invention relates to a method for reducing tungsten cathode corrosion in a boron ion implantation system having a tungsten cathode, the method comprising hydrogenated isotope-rich trifluoride according to various embodiments disclosed herein. And generating boron implanted species for implantation of boron ions in the system by ionization of the boron (BF ₃ ) dopant source gas composition.

Another aspect of the present invention is a boron dopant source gas composition comprising a hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition according to various embodiments disclosed herein for use in a boron ion implantation system. It relates to a method of improving the operating performance of a boron ion implantation system comprising supplying.

In a further aspect, the present invention provides boron implantation from a boron dopant source gas composition comprising a hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition according to various embodiments disclosed herein in a boron ion implantation system. It relates to a method of improving the operational performance of a boron ion implantation system comprising generating species.

Thus, the present invention contemplates a hydrogen/enriched boron trifluoride dopant source gas composition for ion implantation of boron, wherein the composition is a beam with surprisingly effective reduction in the generation of F+, W+ and WF _x + beam components. It contains 2 to 6.99% by volume of hydrogen as a composition range in which the current reduction is maintained at a very low level, for example 0% to 8% reduction of the boron ion beam current. The reduction of the boron ion beam current can be determined by comparing the boron ion beam current when hydrogen is present in the dopant gas in an amount selected for the boron ion beam current in the absence of hydrogen. Thus, the hydrogenated isotope-rich boron trifluoride composition of the present invention maintains a high boron ion beam current while substantially reducing the amount of unwanted beam components including tungsten and tungsten fluoride ionic species, thereby The source life can be significantly extended, improving the high efficiency obtained by using isotope-rich boron trifluoride, and significantly reducing the maintenance required by the ion implantation device, for example with regard to cathode re-metallization and replacement. Can be reduced.

In another aspect, the present invention relates to a method of improving the beam stability and ion source lifetime of a boron doped ion implantation system including a cathode, wherein the method comprises: a boron dopant source gas composition and a boron doped ion implantation system. Introducing into a source chamber, by operating the boron doped ion implantation system to ionize the boron dopant source gas composition in the ion source chamber, to generate a beam of boron dopant species, and send it to a substrate in the ion implantation system to ions Boron doping the substrate in the injection system with a boron dopant species, wherein the dopant source gas composition comprises: (i) boron trifluoride in which an atomic mass of 11 boron ( ¹¹ B) is isotope-rich than its natural abundance, and (ii) hydrogen in an amount of 2 to 6.99% by volume based on the total volume of boron trifluoride and hydrogen in the composition, wherein the weight change (growth or loss) of the cathode during such operation is different from the hydrogen concentration Is minimized in relation to In this way, the ion source chamber may contain a component comprising tungsten, for example the cathode may comprise a tungsten filament. This method also minimizes variations in bias power and filament current. Thus, it would provide an advantage for more stable beam conditions and longer source lifetime than achievable with isotope-rich boron trifluoride without the presence of hydrogen. In some embodiments, hydrogen is in the range of 2 to 6.5% by volume, based on the total volume of boron trifluoride and hydrogen in the composition, in the hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition described above, wherein From 2.5 to 6.25% by volume based on the total volume of boron trifluoride and hydrogen in the composition, from 3 to 6% by volume based on the total volume of boron trifluoride and hydrogen in the composition, of boron trifluoride and hydrogen in the composition It may be present in the range of 4 to 6% by volume based on the total volume, or in an amount of 5% by volume, based on the total volume of boron trifluoride and hydrogen in the composition.

Referring now to the drawings, FIG. 1 is a schematic cross-sectional view of an exemplary fluid supply package 200 comprising a pressure-controlled fluid storage and dispensing vessel, wherein the hydrogenated concentrated boron trifluoride dopant source gas composition of the present invention is It can be provided for storage and distribution of the composition. One gas supply vessel described in US Pat. Wherein the one or more gas pressure regulators are disposed in the interior volume of the gas supply vessel so that the low pressure source gas composition is used to generate ionic species for ion implantation, for applications such as ion implantation, low pressure, For example, it can provide for the distribution of gas in a device operating at a corresponding low pressure in subatmospheric pressure.

The fluid supply package 200 includes a fluid storage and dispensing container 212 comprising a floor 216 and a cylindrical side wall 214 that jointly surrounds an interior volume 218 of the container. The sidewalls and floors can be formed from any suitable manufacturing material, such as metal, gas-impermeable plastic, fiber-resin composite material, or the like, suitable for the pressure level maintained in the container for storage and distribution purposes.

At its upper end 220, the container features a neck 221 defining a port opening 222 constrained by an inner side wall 223 of the neck 221. The inner side wall 223 may be threaded with the valve head 225 including the valve body 226, or may be otherwise configured to be complementary to engageably engage, and the valve body 226 is complementary. It can be threaded separately, or otherwise configured for this engagement.

In this manner, the valve head 225 is leak-tight to retain the hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition in the interior volume 218 at the desired storage conditions. tight) manner with the container 212.

The valve head body 226 is defined with a central vertical passage 228 for distribution of the hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition from the vessel 212. The central vertical passage 228 communicates with the fluid discharge passage 230 of the fluid discharge port 229 as shown.

The valve head body includes a valve element 227 that is coupled with a valve actuator 238 (hand wheel or pneumatic actuator) for selective manual or automatic opening or closing of the valve. In this way, the valve actuator can be opened to flow gas through the central vertical passage 228 to the fluid outlet port 229, or alternatively, physically close the valve actuator, so that the central vertical passage ( Flow of the hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition from 228 to the fluid outlet port 229 can be stopped.

Thus, the valve actuator may be any of a variety of suitable types, such as a manual actuator, a pneumatic actuator, an electromechanical actuator, or the like, or any other suitable device for opening and closing a valve in the valve head.

Thus, the valve element 227 is a flow control valve in which the hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition dispensed from the vessel comprises a valve element 227 disposed downstream of the regulator. It flows through the regulator before flowing through.

The valve head body 226 also includes a filling passage 232 formed to communicate with the filling port 234 at its top. Fill port 234 is shown in Figure 1, capped by fill port cap 236, fills the container and stores and distributes hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition. Protects the charging port from contamination or damage when placed in use for.

The filling passage at its bottom exits the valve head body 226 at its bottom surface, as shown. When the filling port 234 is coupled with the source of the hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition contained in the vessel, the gas flows through the filling passageway to the internal volume 218 of the vessel 212 ) Can flow.

An extension pipe 240 including an upper particle filter 239 therein is coupled to the lower end of the valve head body 226. The upper regulator 242 is mounted at the end of the extension tube 240. The upper regulator 242 is secured to the bottom of the tube in any suitable manner, for example by providing internal threading at the bottom of the tube, where the regulator 242 can be threadedly engaged.

Alternatively, the upper regulator is coupled to the lower end of the extension tube by a compression fitting or other leak-tight vacuum and pressure fitting, or for example welding, brazing, soldering, melt-bonding. By, or by suitable mechanical bonding means and/or methods.

The upper regulator 242 is disposed in series relationship with the lower regulator 260 as shown. For this purpose, the upper and lower regulators are provided by complementary threading comprising threading on the lower extension of the upper regulator 242, and threading engageably engageable with the upper extension of the lower regulator 260. They can be threaded together.

Alternatively, the upper and lower regulators may be coupled to each other in any suitable manner, for example by means of bonding or fitting, adhesive bonding, welding, brazing, soldering, etc., or the upper and lower regulators may be used as components of a dual regulator assembly. It can be configured integrally.

At its lower end, a lower regulator 260 is coupled to a high efficiency particle filter 246.

The high-efficiency particle filter 246 comprises regulator elements and valves from particulates or other contaminating species that may be present in the hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition flowing through the regulator and valve in operation of the device. It serves to prevent contamination of element 227.

The embodiment shown in FIG. 1 also provides high efficiency particles disposed in the extension tube 240 to provide additional particulate removal capability and ensure the high purity of the distributed hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas. It has a filter 239.

Preferably, the regulator has at least one particle filter in series flow relationship with it. Preferably, as shown in the embodiment of FIG. 1, the system includes a particle filter downstream of the regulator(s) as well as a regulator in the fluid flow path from the vessel interior volume 218 to the fluid outlet port 229. Includes a particle filter upstream of (s).

Thus, the valve head 225 of the embodiment of FIG. 1 provides a two-port (one port is a gas fill port 234 and the other port is a gas discharge port 229) valve head assembly.

The pressure regulators of the embodiment of FIG. 1 are of the type each comprising a diaphragm element associated with a poppet-retaining wafer. The wafer is then connected to the stem of the poppet element as part of a pressure sensing assembly that precisely controls the outlet fluid pressure. When the outlet pressure increases slightly above the set point, the pressure-sensing assembly contracts, and when the outlet pressure decreases slightly, the pressure-sensing assembly expands. The contraction or expansion serves to translate the poppet element to provide precise pressure control. The pressure sensing assembly has a preset or set set point for a given application of a fluid storage and dispensing system.

As shown, a gas discharge line 266 comprising a flow control device 268 therein is coupled with a discharge port 229. With this arrangement, the flow control device in the gas discharge line allows the hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition from the storage and distribution vessel to flow through the upstream (bottom) regulator 260 and then From the container 212 (e.g., a semiconductor manufacturing plant) opened in the dispensing mode of the fluid storage and dispensing package 200 when flowing through the downstream (upper) regulator 242 to the valve head for the discharge port 229 , A flat-panel display manufacturing plant, a solar panel manufacturing plant, or other processing facility in which an ion implantation device is arranged for boron for doping of the substrate particles) to the associated ion implantation process facility 270. The flow control device 268 can be of any suitable type, and in various embodiments can include a mass flow controller.

The hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition distributed in this manner will be present at a pressure determined by the set point of the regulator 242.

The respective set points of regulator 260 and regulator 242 in the embodiment of FIG. 1 may be selected or preset to any suitable value to accommodate the particular preferred boron ion implantation end application.

For example, the lower (upstream) regulator 260 can have a set point ranging from about 20 psig to about 2500 psig. The upper (downstream) regulator 242 can have a set point higher than the pressure set point of the lower (upstream) regulator 260, for example in the range of about 1 torr to 2500 psig.

In one exemplary embodiment, the lower (upstream) regulator 260 has a set point pressure value ranging from about 100 psig to about 1500 psig, and the upper (downstream) regulator 242 has a range of about 1 torr to 2500 psig. It has a set point pressure value, where the lower (upstream) pressure set point is higher than the set point of the upper (downstream) regulator.

The set point of the regulator in the series regulator assembly can be set at any suitable ratio relative to each other, in a two-regulator assembly as shown in FIG. 1, but the upstream regulator in a preferred implementation is advantageously the setting of the downstream regulator. It has a pressure set point that is at least twice the point value (measured in the same measuring pressure unit).

In the embodiment of Figure 1, the lower and upper regulators are aligned coaxially with each other to form a regulator assembly with a particulate filter at either end. As a result of this arrangement, the hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition dispensed from vessel 212 has a very high purity.

As a further variant, the particulate filter is a hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source to be distributed impurity species present in the gas composition (e.g., decomposition products derived from the reaction or decomposition of the gas in the vessel) It may be coated or impregnated with a chemical adsorbent selective for In this way, the hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition flowing through the particulate filter is purified in place along the flow path as it is dispensed.

In one exemplary embodiment of a fluid storage and dispensing system of the type shown in FIG. 1, container 212 is a 3AA 2015 DOT 2.2 liter cylinder. High efficiency particle filter 246 is a Mott Corporation with a metal filtration medium sintered in a housing of 316L VAR/electropolished stainless steel or nickel capable of removing more than 99.9999999% of particles up to 0.003 micron diameter. ) (GasShield ^TM PENTA ^TM point-of-use fluid filter available from Farmington, CT). The high efficiency particle filter 239 is a mode standard 6610-1/4 in-line filter commercially available from Morte Corporation (Farmington, CT). The regulator is an HF series Swagelok® pressure regulator, where the upper (downstream) regulator 242 has a set pressure in the range of 100 Torr to 100 psig and the lower (upstream) regulator 260 is from 100 psig to 1500 psig. Has a set pressure in the range, wherein the set point pressure of the (downstream) regulator 260 is at least twice the set point pressure of the upper (downstream) regulator 242. In certain embodiments, the upper (downstream) regulator 242 can have an inlet pressure of 100 psig and an outlet pressure of 500 torr, and the lower (upstream) regulator 260 has an inlet pressure of 1500 psig and an outlet pressure of 100 psig. Can have pressure.

Figure 2 is a schematic diagram of an ion implantation system illustrating a mode of operation according to the present invention, wherein the hydrogenated rich boron trifluoride dopant source gas composition of the present invention is supplied to an ion implanter to implant boron into the substrate.

As shown in FIG. 2, the implantation system 10 includes an ion implanter 12 disposed in receptive relationship to the gas supply packages 14, 16 and 18 for delivering gas to the implanter.

The gas supply package 14 includes a container containing gas. In some cases, the vessel includes a valve head assembly 22 having an outlet port 24 coupled to a gas supply line 44. The valve head assembly 22 is provided with a hand wheel 38 for manually adjusting the valves in the valve head assembly to perform distribution or otherwise closed storage of the gas contained in the container 20, if necessary. For this purpose, it is converted equally in the fully open position and the fully closed position. Instead of providing a hand wheel 38, the gas supply package 14 may be provided with an automatic valve actuator, such as a solenoid or air valve actuator, for converting the valve in the package's valve head assembly to an appropriate open or closed position. .

The gas may also be included in the gas supply packages 16 and 18, each configured in a similar manner to the gas supply package 14. The gas supply package 16 includes an actuator for a valve in a vessel 26 or alternatively a valve head assembly with a valve head assembly 28 to which a hand wheel 40 is connected. The valve head assembly 28 includes an exhaust port 30 to which a gas supply line 52 is connected. Similarly, the gas supply package 18 is a container 32 equipped with a valve head assembly 34 to which the hand wheel 42 is coupled or a corresponding actuator for actuation of a valve in the valve head assembly 34. Includes. The valve head assembly 34 also includes a discharge port 36 coupled to a gas discharge line 60.

In the illustrated arrangement, at least one of the gas supply packages 14, 16, and 18 provides the hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition of the present invention to the ion implanter 12. Contains for sequential supply of the gas composition. Additionally or alternatively, one of the gas supply packages, e.g., gas supply package 14, may contain hydrogen, and the other gas supply package, e.g., gas supply package 16, is isotope-rich. A hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition by flowing the hydrogen and boron trifluoride components of the composition into the mixing chamber in each gas supply line 44 and 52, which may contain boron trifluoride. Can be configured at the point of use. Since the gas supply package 18 in such a batch may contain additional isotope-rich boron trifluoride, both gas supply packages 16 and 18 provide isotope-rich BF ₃ , whereby the gas supply package 16 ) When the inventory of boron trifluoride is exhausted, the valve in the valve head of the gas supply package 16 is closed, and isotopically-rich at the opening of the valve in the valve head of the gas supply package 18. The active distribution of boron fluoride can be switched to the gas supply package 18. This arrangement accommodates the relative ratio in the hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition, with a small amount of hydrogen gas added to the isotope-rich boron trifluoride.

Accordingly, the present invention provides a boron dopant gas composition supply package including (a) a first gas storage and distribution container containing an isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition, and (b) hydrogen gas supply Consider a dopant source gas composition supply kit comprising a package, wherein the hydrogen gas supply package includes a second gas storage and distribution container containing hydrogen gas.

As a further variant of the system shown in Figure 2, each gas supply package 14 and 16 may contain a hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition, such that the on- On exhaustion of the stream the other gas supply package can be switched to a distribution operation for continuity of the boron doping operation in the ion implanter, so that the gas supply package 18 can contain a cleaning gas. In this variant arrangement, the boron doping operation can be performed by sequentially dispensing the hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition from each of the gas supply packages 14 and 16, wherein the boron doping operation is After termination, the package is switched to a new package of hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition while the valve of the gas supply package 18 is opened to allow the flow circuit and downstream ion implanter 12 ), the cleaning gas can be distributed. For this purpose, the gas supply package 18 may contain any suitable cleaning gas, for example nitrogen trifluoride, xenon difluoride, hydrogen fluoride, or other suitable cleaning gas.

In order to control the flow from each gas supply package, each gas supply line 44, 52, and 60 is provided with flow control valves 46, 54, and 62 therein, respectively.

The flow control valve 46 is provided with an automatic valve actuator 48 having a signal transmission line 50 connecting the actuator to the CPU 78, and the CPU 78 transmits a control signal from the signal transmission line 50. Transmission to the valve actuator adjusts the position of the valve 46 to correspondingly control the flow of gas from the vessel 20 to the mixing chamber 68.

In a similar manner, the gas discharge line 52 includes a flow control valve 54 coupled with a valve actuator 56 that is connected to the CPU 78 by a signal transmission line 58. Accordingly, the flow control valve 62 of the gas discharge line 60 is provided with a valve actuator 64 connected to the CPU 78 by a signal transmission line 66.

In this way, the CPU can operably control the flow of each gas from the corresponding vessels 20, 26 and 32.

When the gas flows simultaneously into the mixing chamber 68 (co-flow), such as in the case of mixing hydrogen from one of the vessels with the isotope-rich boron trifluoride from the other or another vessel, After mixing in the mixing chamber 68, the product gas composition is then discharged to the supply line 70 for passage to the ion implanter 12. Accordingly, the present invention contemplates a method of operating an ion implantation system, wherein the ¹¹ B-isotope-rich boron trifluoride from the first gas supply package together with hydrogen gas from the second gas supply package, (i) Boron trifluoride having an atomic mass of 11 ( ¹¹ B) is isotope-rich than its natural abundance, and (ii) hydrogen in an amount of 2 to 6.99 vol% based on the total volume of boron trifluoride and hydrogen in the composition. The relative ratio of the boron trifluoride and hydrogen constituting the dopant source gas composition in the ion source chamber is co-flowed into the ion source chamber of the ion implantation system.

Thus, when only a single gas supply package 14, 16 or 18 is operated in a distribution mode, the corresponding hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition is then regulated by the associated flow control valve. It flows through the mixing chamber accordingly and passes through the supply line 70 to the ion implantation device.

The supply line 70 is coupled with a gas analyzer 74 and a bypass flow loop consisting of bypass lines 72 and 76 in communication with the supply line. Thus, the gas analyzer 74 receives the secondary stream from the main flow in the supply line 70, responsively generates a monitoring signal correlation such as the concentration of the gas stream, the flow rate, and the analyzer 74 and the CPU ( The monitoring signal is transmitted from the signal transmission line connecting 78). In this way, the CPU 78 receives a monitoring signal that monitors the concentration, flow rate, etc. of the gas stream, processes the same, and suitably, the respective valve actuators 48, 56 and 64, or a selected one of them. Reactively generate an output control signal sent to the ion implanter to effect the desired distribution operation of the hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition to the ion implanter. The gas analyzer 74 and CPU 78, equipped with auxiliary signal transmission lines and actuators, are ground to form a hydrogenated isotope-rich boron trifluoride (BF3) dopant source gas composition containing a desired concentration of hydrogen. land) Construct a monitoring and control system that can be operatively used for hydrogen and isotope-rich boron trifluoride.

The ion implanter 12 creates an effluent flowing from the effluent line 80 to the effluent treatment unit 82, which treats the effluent by effluent treatment operations including scrubbing, catalytic oxidation, and the like. The treatment produces a treated gaseous effluent that exits the treatment unit 82 in a vent line 84 and can be passed to further treatment or other disposal.

The CPU 78 may be of any suitable type and, as described above, a general purpose programmable computer, a special purpose programmable computer, a programmable logic controller, a microprocessor, or a signal processing and output control signal or signal of a monitoring signal. It can contain a variety of other computational units that are effective for generation.

Thus, the CPU is programmed to perform periodic operations involving simultaneous flows of gases from two or all three sources 14, 16 and 18, or, alternatively, to allow each gas to flow sequentially. It can be composed of. Thus, any flow mode can be accommodated, including co-flow of a gas mixture, or sequential gas flow.

Thus, the boron doping of the substrate in the ion implanter is hydrogenated by mixing hydrogen and enriched boron trifluoride as a premixed gas composition or from a separate gas supply package when in use, or in combination or sequentially with other gas species. It will be appreciated that this can be done in any of a variety of ways to use the isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition. Thus, the hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition is a hydride gas in various implementations of the ion implantation system shown in FIG. 1 or in an ion implantation system correspondingly configured for operation according to the present invention. It will be appreciated that it can be used in various ways with fluoride gas, rare gas gas, oxide gas or other gas.

Accordingly, the hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition of the present disclosure is as a premix composition, as may be desirable in a given implementation of the dopant source gas composition of the present invention in certain ion implantation equipment. It will be appreciated that, or alternatively, the hydrogen and boron trifluoride components of such compositions are configured at the point of use from the respective gas supply package.

Referring now to Figure 3, the hydrogen/enriched boron trifluoride co-flow ratio (0 to 0.6) flowing into the ion chamber of the ion implantation device at an isotope-rich BF ₃ flow rate of 2.75 standard cubic centimeters per minute (sccm). A graph of the B+ beam current in milliamps as a function of volume H ₂ /volume BF ₃ ) is shown, showing the beam performance of the hydrogenated isotope-rich boron trifluoride dopant source gas composition of the present invention.

The enriched boron trifluoride gas in the hydrogenated isotope-rich boron trifluoride dopant source gas composition used to generate the data shown in FIG. 3 was substantially pure (> 99.95 vol%) ¹¹ BF ₃ . The arc voltage of the ion implantation device used to generate these data was 90 V, at which time the source beam current was 25 mA and the extraction voltage was 20 kV.

The data in FIG. 3 show that the B+ beam current for the isotope-rich BF ₃ alone is about 6.5 mA. It has been found that at values of the hydrogen/boron trifluoride co-flow ratio above 0.07, the beam current decreases rapidly. It has been found that a hydrogen/boron trifluoride co-flow ratio of less than 0.02 provides inadequate hydrogen to inhibit tungsten fluorine reaction and tungsten deposition, coating and cathode growth of tungsten in the operation of the ion implantation system.

Accordingly, the present invention considers a hydrogen/enriched boron trifluoride dopant source gas composition for ion implantation of boron, wherein the composition has a very low level of beam current reduction as compared to the baseline boron ion beam current, For example, as a composition range in which the generation of F+, W+ and WF _x + beam components is effectively reduced while being maintained in the range of 0% to 8% reduction of the B+ beam current, about 2 to about 6.99% by volume hydrogen, more preferably Contains about 5% by volume hydrogen. Accordingly, the hydrogenated isotope-rich boron trifluoride composition of the present invention maintains a high boron ion beam current while substantially reducing the amount of undesired beam components including tungsten and tungsten fluoride ionic species, thereby providing the source of the cathode. By making it possible to extend the lifetime, it improves the high efficiency obtained by the use of isotope-rich boron trifluoride, and reduces the maintenance required by the ion implantation device, for example in connection with cathode re-metallization and replacement. Let it.

Figure 4, (i) only the substantially pure (> 99.95 vol%) ¹¹ BF flow, (ii) of the lower H ^_2/11 BF ₃ by volume, substantially pure (> 99.95 vol%) ¹¹ BF ₃ and hydrogen in the co-flow, and (iii) a high H ^_2/11 BF ₃ by volume, of substantially pure hydrogen (> 99.95 vol%) ¹¹ BF ₃ and hydrogen in the ball-of, 170-300AMU range shown for flow W + and WF _x + (x = 1, 2, 3, 4, 5 and 6) showing the beam current values for B+, F+, HF+, BF+, BF2+ and W++ ions by inset spectral segments representing the beam current values for the ions. A graph comparing the beam spectrum of the beam current in milliamps as a function of the atomic mass unit (AMU) value. The flow rate of substantially pure ¹¹ BF ₃ in all test runs was 2.75 sccm, the source beam current was 25 mA, with the arc voltage 90 V and the extraction voltage 20 kV.

The data in Figure 4 show that the hydrogen co-flow significantly reduces the generation of W+ and WF _x (x = 1, 2, 3, 4, 5 and 6) beam spectral components, which are lower than the levels produced in the absence of hydrogen. Show that it is effective.

5 is a graph of 0 to shown in milliamps as a function of the 0.6 H ^_2/11 BF ₃ volume ratio of F +, HF +, W +, and WF + beam current, wherein for data for each of the ionic species is F + diamond symbol ( ◆), HF+ is indicated by a circular dot symbol (●), W+ is indicated by a square symbol (■), and WF+ is indicated by a triangle symbol (▲). The boron trifluoride used to generate these data was substantially pure (> 99.95 vol%) ¹¹ BF ₃ . The boron trifluoride used to generate these data was substantially pure (> 99.95 vol%) ¹¹ BF ₃ .

The data in Figure 5 show that the F+, W+ and WF+ beam currents are substantially reduced by the presence of hydrogen. It has been found that the HF+ beam current can be maintained at a very low level ranging from 2 to 6.99 vol% H ₂ , more particularly about 5 vol% H ₂ concentration in the H ₂ /enriched BF ₃ dopant source gas composition of the present invention. .

6 is shown in milliamps as a function of 0 to 0.6 H ^_2/11 BF ₃ volume ratio of, F +, as a normalized graph corresponding to the HF +, W +, and WF + beam current, where x is in the H ₂ / BF ₃ ratio And the F+, HF+, W+, and WF+ beam currents were normalized to the B+ beam current, where the data for each ionic species is a diamond symbol (◆) for F+, a circular dot symbol (●), and W+ for HF+. Is indicated by a square symbol (■) and for WF+ by a triangle symbol (▲).

Thus, the dopant source gas composition of the present invention provides an effective balance in maintaining the high beam current of the boron implanted species, while W+ and WF _x + (x = 1, 2, 3, 4, 5, and 6) beam current And tungsten fluoride reaction. For example, the reduction in the beam current of a selected boron implanted species, such as B+ or BF2+, is by comparing the boron implanted species beam current when hydrogen is present in the dopant gas in a selected amount versus the boron implanted species beam current in the absence of hydrogen. Can be determined. In some cases, the reduction in boron implanted species beam current is 0% to less than 10%; 0% to less than 9%; 0% to less than 8%; Or from 0% to less than about 5%. This balance can help reduce tungsten deposition, coating and cathode growth of tungsten. A suitable balance of boron trifluoride/hydrogen mixtures can also be used to prevent the so-called “punch through” of the cathode due to sputtering.

The dopant source gas composition of the present invention can be used in boron doping applications where the ion implantation system is "tuned" for the selection of various boron ionic implant species. For example, in various applications, the ion implantation system can be tuned for B+ doping of the substrate. In another application, the ion implantation system can be tuned for doping of the BF ₂ + implant species in the substrate. The dopant source gas composition of the present invention can be advantageously used in any of these ion implantation systems tuned for any of a variety of boron ionic implantation species.

When the ion implantation system is tuned for doping of the BF ₂ + implant species in the substrate, a hydrogenated enriched boron trifluoride gas composition, more specifically a hydrogen/enriched boron trifluoride dopant source gas composition for ion implantation of boron. When used, it is another surprising aspect of the present disclosure that a greater reduction in the tungsten mass spectral peak is achieved with respect to the observed reduction for the B+ doping of the substrate, wherein the composition ranges from about 2 to about 6.99 volumes. % Hydrogen, more specifically about 5% by volume hydrogen.

A series of tests were performed using a commercial indirectly heated cathode ion source operating at an arc power of 120 V and 3.4 A, an extraction voltage of 20 kV, and a flow rate of 4 sccm of substantially pure (> 99.95 vol%) ¹¹ BF ₃ Wherein these runs included enriched boron trifluoride hydrogenated using boron trifluoride at the same base flow rate (4 sccm) with hydrogenation in an optimized percentage. In the beam process, an ion source with an argon pre-warmed for 20 minutes and, in particular injection longitudinal beam B + or BF ₂ + was adjusted by optimizing the magnetic source, the selected location, and the analyzer magnet of the ion implanter. The resulting test beam was run for 11 hours under conditions optimized to ensure beam stability, generating a mass spectrum, and then the source was post-warmed with argon for about 15 minutes.

Figure 7 shows B+, F+, HF+, BF+, by inset spectral segments representing beam current values for W+ and WF _x + (x = 1, 2, 3, 4, 5 and 6) ions in the 170-300 AMU range. A comparison graph of the beam spectrum of the beam current in milliamps as a function of atomic mass unit (AMU) values showing the beam current values for BF2+ and W++ ions, where the ion implantation system is substantially non-hydrogenated in both cases. Using pure (> 99.95% by volume) ¹¹ BF ₃ , it was adjusted for the B+ ion implantation species in the first run and the BF ₂ + ion implantation species in the second run. As reflected in the graph, there were significant changes in the fluorine (F+) peak and tungsten (W+) peak in each adjusted plant system.

Figure 8 shows B+, F+, HF+, BF+, by inset spectral segments representing beam current values for W+ and WF _x + (x = 1, 2, 3, 4, 5 and 6) ions in the 170-300 AMU range. A beam spectrum comparison graph of the beam current in milliamps as a function of atomic mass unit (AMU) values showing beam current values for BF2+ and W++ ions, wherein the ion implantation system is substantially non-hydrogenated in the first run. Pure (> 99.95 vol%) ¹¹ BF ₃ was used for B+ ion implantation species (green spectrum) and substantially pure (> 99.95 vol%) ¹¹ BF ₃ hydrogenated in the second run in the second run was used. and BF ₂ + ion implantation was adjusted for the kinds (red spectrum; the H ^_2/11 BF ₃ optimization of volume ratio 0.05). As reflected in the graph, similar B+ beams were produced in both runs, and W+ and WF _x +(x) in the use of a hydrogenated ¹¹ BF ₃ dopant gas source compared to the use of a non-hydrogenated ¹¹ BF ₃ dopant gas source composition. = 1,2,3,4,5 and 6) The peaks decreased.

Figure 9 is B+, F+, HF+, BF+, by inset spectral segments representing beam current values for W+ and WF _x + (x = 1, 2, 3, 4, 5 and 6) ions in the 170-300 AMU range. A beam spectrum comparison graph of the beam current in milliamps as a function of atomic mass unit (AMU) values showing beam current values for BF2+ and W++ ions, wherein the ion implantation system is substantially non-hydrogenated in the first run. Pure (> 99.95 vol%) ¹¹ BF ₃ was used for B+ ion implantation species (green spectrum) and substantially pure (> 99.95 vol%) ¹¹ BF ₃ hydrogenated in the second run in the second run was used. and BF ₂ + ion implantation was adjusted for the kinds (red spectrum; the H ^_2/11 BF ₃ optimization of volume ratio 0.05). As reflected in the graph, was similar to B + beam is generated by the two performed, W + and WF ₆ + peak of non-use of hydrogenated as compared to the use of hydrogenated ¹¹ BF ₃ dopant gas source composition ¹¹ BF ₃ dopant gas source composition Significantly decreased in.

Data for each run of FIGS. 10, 11, 12 and 13 are presented in Table 1 below.

Table 1

10 is a graph showing a plot of cathode weight change with respect to a volume percent of hydrogen gas having a dopant gas of B+. As shown in FIG. 10, the cathode weight change for BF ₃ /H ₂ in 5% H ₂ did not follow the trend of cathode weight change from 0% to 13%. The weight loss of the BF ₃ /5% H ₂ composition was 0% or less than 13% H ₂ .

11 is a graph showing the plotted cathode weight change with respect to the volume percent of hydrogen gas in which the dopant gas is B+. As shown in FIG. 11, the anti-cathode weight change for BF ₃ /H ₂ in 5% H ₂ also did not follow the trend from 0% to 13%. The weight loss of BF ₃ /5% H ₂ was almost equal to 0 %.

12 is a graph showing a change in cathode weight plotted against a volume percent of hydrogen gas in which the dopant gas is BF ₂ +. As shown in FIG. 12, the cathode weight change for BF ₃ /H ₂ in 5% H ₂ did not follow the trend of cathode weight change from 0% to 13%.

13 is a graph showing a change in cathode weight plotted against a volume percent of hydrogen gas having a dopant gas of BF ₂ +. As shown in Figure 13, the anti-cathode weight change for BF3/5% H ₂ is closer to the 0% H ₂ condition and slightly deviates from the 0% to 13% trend.

From the above data, it appears that the bias power is significantly affected by hydrogen in the dopant source gas composition, with the B+ dopant adjustment having a larger bias power change compared to the BF ₂ + dopant adjustment. With respect to the weight change of the cathode and anti-cathode components, in an ion implantation system tuned for B+ doping, the use of a hydrogenated ¹¹ BF ₃ dopant source composition according to the present invention is a non-hydrogenated ¹¹ BF ₃ dopant. There was a 7% change in cathode weight loss compared to the use of the source composition. In an ion implantation system tuned for BF ₂ + doping, using an ¹¹ BF ₃ dopant source composition hydrogenated according to the present invention results in a cathode weight loss of more than 4 times.

The use of the hydrogenated isotope-rich boron trifluoride dopant source gas composition of the present invention produces less cathode weight loss than the corresponding non-hydrogenated isotope-rich boron trifluoride dopant source gas composition, while simultaneously producing an ion source. Providing less tungsten transport in the is a surprising and beneficial result. Thus, the dopant source gas composition of the present invention achieves substantial advances in the art.

Although the present invention has been described herein with reference to specific aspects, features and exemplary embodiments, the usefulness of the present invention is not limited thereto, but rather, based on the description herein, to those of ordinary skill in the art. It will be appreciated that, as suggested by itself, many other variations, modifications and alternative embodiments are extended and included. Correspondingly, the invention claimed hereinafter is intended to be broadly interpreted and interpreted as including all such variations, modifications and alternative embodiments within its spirit and scope.

Claims (19)

As a hydrogenated isotopeally enriched boron trifluoride (BF ₃ ) dopant source gas composition,
(i) boron trifluoride having an atomic mass of 11 ( ¹¹ B) isotope-rich than its natural abundance, and
(ii) hydrogen in an amount of 4 to 6.5% by volume based on the total volume of boron trifluoride and hydrogen in the composition.
A composition consisting essentially of. delete delete delete delete The method of claim 1,
The composition, wherein hydrogen is present in an amount of 5% by volume, based on the total volume of boron trifluoride and hydrogen in the composition. As a hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition,
(i) isotopically-rich boron trifluoride in an excess of 99% of boron of atomic mass 11 ( ¹¹ B), and
(ii) hydrogen in an amount of 5% by volume based on the total volume of boron trifluoride and hydrogen in the composition.
A composition consisting essentially of. The supply of a boron dopant gas composition comprising a gas storage and distribution vessel holding the hydrogenated isotope-rich boron trifluoride (BF ₃ ) dopant source gas composition according to any one of claims 1, 6 and 7 package. delete delete delete (a) ¹¹ B-isotope-rich boron trifluoride from the first gas supply package and (b) hydrogen gas from the second gas supply package, (i) boron of atomic mass 11 ( ¹¹ B) is naturally present A dopant source gas composition in an ion source chamber consisting essentially of boron trifluoride, which is more isotope-rich than the amount, and (ii) hydrogen in an amount of 4 to 6.5% by volume, based on the total volume of boron trifluoride and hydrogen in the composition. A method of operating an ion implantation system comprising co-flowing into the ion source chamber of the ion implantation system, with the relative ratio of boron trifluoride and hydrogen making up. Introducing a boron dopant source gas composition into an ion source chamber of a boron doped ion implantation system, and
Operate the boron doped ion implantation system to ionize the boron dopant source gas composition in the ion source chamber, generate a beam of boron dopant species, and send it to a substrate in the ion implantation system to transfer the substrate in the ion implantation system to a boron dopant. Doping boron with species
As a method comprising a, wherein
The dopant source gas composition comprises (i) boron trifluoride in which an atomic mass of 11 boron ( ¹¹ B) is isotope-rich than its natural abundance, and (ii) 4 based on the total volume of boron trifluoride and hydrogen in the composition. Consisting essentially of hydrogen in an amount of to 6.5% by volume,
The method, wherein the weight change of the cathode during the operation is minimized with respect to different hydrogen concentrations, and beam stability and ion source lifetime are improved. delete delete delete delete delete The method of claim 13,
The method, wherein the beam current of the boron ion implantation species is reduced by less than 8% as compared to the beam current of the boron ion implantation species in the absence of hydrogen in the ion source chamber.

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